1. Technical Field
The invention relates generally to apparatus for mounting a bearing assembly on a shaft and, more particularly, to such mounting apparatus including a tapered mounting adapter sleeve.
2. Related Prior Art
It is generally known to mount bearing assemblies on a shaft through the use of set screws or eccentric collars which lock the inner ring of the bearing assembly to the shaft. In such designs, the inner ring of the bearing assembly extends longitudinally along the shaft and is incorporated in the mechanisms for sealing the inner ring against the shaft and for locking the bearing assembly on the shaft.
It is also known to provide a bearing assembly with an inner ring which has extending therethrough a tapered bore and which loosely surrounds the shaft. Such bearing assembly designs also include a cylindrical wedge or tapered mounting adapter sleeve that is also placed over the shaft. The sleeve has therein a longitudinally extending slit which allows the sleeve to be placed over the shaft but affords compression or squeezing the sleeve into frictional engagement with the shaft. The sleeve is pulled into engagement with the tapered bore in the inner ring of the bearing assembly. The wedge-like engagement between the tapered sleeve and the tapered bore creates an interference fit between the sleeve and the inner ring, and compresses the sleeve into locked engagement with the shaft. The locked engagement between the inner ring and the sleeve, and between the sleeve and the shaft thereby fixes the inner ring relative to the shaft.
The use of a tapered sleeve in conjunction with a tapered inner ring to mount a bearing assembly on a shaft is advantageous in that this type of bearing assembly mounting accommodates shafts which may have a circumference differing from a nominal specified circumference. Known set screw-mounted or collar-mounted roller bearing assemblies are not as likely to be successfully used with undersized shafts because such arrangements result in premature failure of the bearing assembly mounting. Use of such traditional mounting apparatus on a shaft that is undersized by only several thousands of an inch can cause such problems.
However, the range of shaft sizes that can be accommodated through use of a tapered bearing assembly mounting is limited in part by the width of the slit in the tapered sleeve and the range of available relative longitudinal movement between the inner ring and the tapered sleeve. This range of longitudinal relative movement is determined in large part by the length and angles of the tapers on the inner ring and on the outer surface of the mounting adaptor sleeve. Also, the axial length of the inner ring and the axial length of the tapered sleeve in part determine the range of relative longitudinal movement therebetween.
Another factor limiting the range of shaft sizes that can be accommodated by a bearing assembly is the available space or envelope available in which the bearing assembly must fit when mounted upon the shaft. In general, a bearing assembly designed for large loads requires a larger envelope or pitch diameter than a lighter duty bearing assembly.
It is also known that the use of a tapered bearing assembly mounting is advantageous for applications requiring the use of shafts made of hardened material or for applications wherein the direction of shaft rotation is expected to reverse.